Automatic volume control for land mobile radio

ABSTRACT

The present disclosure provides a radio and method for automatically adjusting, in response to ambient noise, the volume setting of a radio. The radio comprises a microphone for receiving ambient audio and generating a microphone signal; a codec for receiving the microphone signal and generating a processor signal representative of the ambient audio; and processor circuitry operable to receive the processor signal, determine an ambient audio level in response to the processor signal, and determine an adjusted radio volume to generate a radio volume control signal, wherein the adjusted radio volume is determined by calculating a difference between a baseline volume level and ambient audio level and adding a current volume level setting, wherein the codec is also operable to receive the radio volume control signal and generate an output signal to adjust the radio volume setting to maintain a net difference between the adjusted radio volume and ambient audio.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(e), this application claims the benefit of,and hereby incorporates by reference for all purposes, U.S. ProvisionalPatent Application Ser. No. 62/031,785, entitled “Automatic VolumeControl for Land Mobile Radio,” filed Jul. 31, 2014, and namingChristian K. Barker, Joshua Alan Johnson, Stephen Joseph Borer, andMarshall Pommier Schiring as inventors.

FIELD

The present disclosure relates generally to communication systems. Morespecifically, but not by way of limitation, the present disclosurerelates to an apparatus and method for automatically adjusting thevolume setting of a radio in a Land Mobile Radio (LMR) communicationsystem.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Land Mobile Radio (LMR) systems are deployed by organizations requiringinstant communication between geographically dispersed and mobilepersonnel. Current LMR systems can be configured to provide for radiocommunications between one or more sites and subscriber radio units inthe field. A subscriber radio unit (hereinafter “radio”) may be a mobileunit or a portable unit. LMR systems can be as simple as two radio unitscommunicating between themselves over preset channels, or they can becomplex systems that include hundreds of radio units and multiple sites.Typical users of LMR systems include police departments, firedepartments, medical personnel, security personnel, EMS, and themilitary.

Radios deployed in LMR systems may face various difficulties dependingupon their use, environment, and other circumstances, therebycompromising communication in certain situations. For example,firefighters often work in high, unpredictable noise environments wherethe volume of the ambient noise changes unpredictably due to variousfactors, such as changes in the environment. Therefore, a firefightermay need to constantly adjust the volume setting of his portable radioin response to the variations of the ambient noise. However, when afirefighter is fully equipped at a fire scene, his radio is usuallyinaccessible. For example, the radio may be worn in a location that isinconvenient to access, or the firefighter has limited use of his handsbecause he is wearing gloves or using tools. As such, the firefighter isunable to conveniently control the volume setting of his portable radio.

SUMMARY

In one embodiment, the present disclosure provides a land mobile radiofor use in a land mobile radio (LMR) system, the land mobile radioconfigured to automatically adjust a volume setting of the land mobileradio in response to ambient audio, the land mobile radio comprising: afirst microphone configured to receive the ambient audio and generate amicrophone signal in response to receiving the ambient audio; ananalog-to-digital converter configured to receive the microphone signaland generate a processor input signal representative of the ambientaudio; first circuitry configured to receive the processor input signal,determine an ambient audio level in response to the processor inputsignal, and determine an adjusted radio volume to generate a radiovolume control signal, wherein the adjusted radio volume is determinedby calculating a difference between a baseline volume level and theambient audio level and adding a current volume level setting; and adigital-to-analog converter configured to receive the radio volumecontrol signal and generate an output signal to adjust the volumesetting of the land mobile radio such that a net difference ismaintained between the adjusted radio volume and the ambient audio.

In another embodiment, the present disclosure provides a method forautomatically adjusting a volume setting of a land mobile radio inresponse to ambient audio, the method comprising: receiving the ambientaudio at a microphone of the radio and generating a microphone signal;receiving the microphone signal at an analog-to-digital converter andgenerating a processor input signal representative of the ambient audioreceived at the microphone; receiving the processor input signal atfirst processor circuitry and determining an ambient audio level;determining an adjusted radio volume by calculating a difference betweena baseline volume level and the ambient audio level and adding a currentvolume level setting; generating a radio volume control signal based onthe adjusted radio volume; and receiving the radio volume control signaland adjusting the volume setting of the land mobile radio such that anet difference is maintained between the adjusted radio volume and theambient audio.

In yet another embodiment, the present disclosure provides one or morestorage media embodied with computer-executable instructions that, whenexecuted by a processor, perform a method for automatically adjusting avolume setting of a land mobile radio in response to ambient audio, themethod comprising: receiving the ambient audio at a microphone of theradio and generating a microphone signal; receiving the microphonesignal at an analog-to-digital converter and generating a processorinput signal representative of the ambient audio received at themicrophone; receiving the processor input signal at first processorcircuitry and determining an ambient audio level; determining anadjusted radio volume by calculating a difference between a baselinevolume level and the ambient audio level and adding a current volumelevel setting; generating a radio volume control signal based on theadjusted radio volume; and receiving the radio volume control signal andadjusting the volume setting of the land mobile radio such that a netdifference is maintained between the adjusted radio volume and theambient audio.

Further embodiments and apparatuses, including other areas ofapplicability, will become apparent from the description providedherein. It should be understood that the description and specificexamples are intended for purposes of illustration only and are notintended to limit the scope of the present disclosure in any manner.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of various embodiments of the presentinvention and the advantages thereof, reference is now made to thefollowing brief description, taken in connection with the accompanyingdrawings and detailed description, wherein like reference numeralsrepresent like parts, and in which:

FIG. 1 illustrates a block diagram of various components comprising aland mobile radio in accordance with an embodiment of the presentdisclosure;

FIG. 2 illustrates a flow diagram of an embodiment of a method forautomatically adjusting the volume setting of a radio in response toambient audio received at the radio;

FIG. 3 presents a graph illustrating a comparison of ambient audio andradio volume adjusted in accordance with an embodiment of the presentdisclosure;

FIG. 4 illustrates a block diagram of processor circuitry in accordancewith an example embodiment of the present disclosure;

FIG. 5 illustrates an example block diagram of the DSP comprising theprocessor circuitry shown in FIG. 1;

FIG. 6 illustrates an example block diagram of the ARM processorcomprising the processor circuitry shown in FIG. 1; and

FIG. 7 illustrates an example block diagram illustrating an exampleembodiment of the automatic volume control circuitry shown in FIG. 6.

DETAILED DESCRIPTION OF THE FIGURES

In the following detailed description and the attached drawings,numerous specific details are set forth to provide a thoroughunderstanding of the present disclosure. However, those skilled in theart will appreciate that the present disclosure may be practiced, insome instances, without such specific details. In other instances,well-known elements have been illustrated in schematic or block diagramform in order not to obscure the present disclosure in unnecessarydetail. Additionally, for the most part, specific details, and the like,have been omitted inasmuch as such details are not considered necessaryto obtain a complete understanding of the present disclosure, and areconsidered to be within the understanding of persons of ordinary skillin the relevant art.

It is further noted that, unless indicated otherwise, all functionsdescribed herein may be performed in hardware or as softwareinstructions for enabling a computer, radio or other device to performpredetermined operations, where the software instructions are embodiedon a computer readable storage medium, such as RAM, a hard drive, flashmemory or other type of computer readable storage medium known to aperson of ordinary skill in the art. In certain embodiments, thepredetermined operations of the computer, radio or other device areperformed by a processor such as a computer or an electronic dataprocessor in accordance with code such as computer program code,software, firmware, and, in some embodiments, integrated circuitry thatis coded to perform such functions. Furthermore, it should be understoodthat various operations described herein as being performed by a usermay be operations manually performed by the user, or may be automatedprocesses performed either with or without instruction provided by theuser.

The present disclosure provides a radio and method for automatically andcontinuously adjusting, in response to ambient noise, the volume settingof a radio for use in a Land Mobile Radio (LMR) system. FIG. 1illustrates an example embodiment of circuitry components comprising aradio 100, including a microphone 101 coupled to the radio 100 and aradio speaker 102. As shown in FIG. 1, the radio 100 includes a codec103 and processor circuitry 104, which may be implemented, in someembodiments, as a system on a chip (SoC). It should be appreciated thatthe radio components may be fully integrated with the radio unit itselfor discrete components separate from, but connected or coupled to, theradio unit. For example, in some embodiments, the microphone 101 may bea microphone physically located on the radio unit. In other embodiments,the microphone 101 may be coupled to the radio as a shoulder microphoneor other external microphone separate from, but coupled via wired orwireless connection to, the radio unit 100. In some embodiments, themicrophone 101 and speaker 102 may be integrated as a single unit. Insome embodiments, the speaker 102 may be a speaker physically located onthe radio unit. In other embodiments, the speaker 102 may be an externalspeaker separate from, but coupled via wired or wireless connection to,the radio unit 100.

The circuitry illustrated in FIG. 1 is now described with reference toan embodiment of a method for automatically adjusting the volume settingof a radio in response to ambient audio received at the radio. Themethod is illustrated by the flow diagram of FIG. 2. In accordance withthe embodiment of the method illustrated in FIG. 2, at 200, theprocessor circuitry 104 determines whether the radio is operating in atransmit state or if the speaker 102 is activated. If either of theseconditions are true, then the method is paused until both conditions arefalse, before moving to the next block. In some embodiments, thedetermination in block 200 may be performed continuously as the radiooperates, and not just as a single occurrence in sequential order withother blocks in the method. In some embodiments, the volume may beadjusted every second. In some embodiments, the automatic volume controlfeature may be paused when a user is activating radio buttons orperforming other such operations.

In accordance with the embodiment illustrated in FIG. 1, and at block201 of FIG. 2, the radio microphone 101 receives the ambient audio 105and generates a microphone signal 106, wherein the microphone signal 106is typically an analog signal representative of the ambient audioreceived at the microphone 101. At block 202, the codec 103 receives themicrophone signal 106 and generates a processor input signal 107 that isrepresentative of the ambient audio received at the radio microphone101. In some embodiments, the codec 103 comprises analog-to-digitalconverter circuitry, and the microphone signal 106 is converted to adigital signal, which is produced by the codec 103 as the processorinput signal 107.

At block 203, the processor input signal 107 is received by theprocessor circuitry 104, and the processor circuitry 104 determines anambient audio level, which is a value that is representative of a volumelevel of the ambient audio received at the microphone 101. This processis discussed in greater detail below.

At block 204, the processor circuitry 104 determines an adjusted radiovolume and generates a radio volume control signal 108. In someembodiments, the adjusted radio volume is calculated by subtracting abaseline volume level from the ambient audio level, and then adding acurrent volume level setting. As explained in greater detail below, thebaseline volume level is a value that represents a volume level for usein a quiet environment (i.e., an environment with little or no ambientaudio). The current volume level setting is a value that isrepresentative of the current radio speaker volume setting.

Reference is made now to FIG. 3, which presents a graph illustrating theambient audio 105 and the radio volume 302 (this is not the currentradio volume level setting, but rather, the adjusted volume of theradio), which is adjusted in accordance with the present disclosure tomaintain a volume level greater than the ambient audio 105 (i.e., netdifference 304). The adjusted radio volume (element 615 discussed belowwith reference to FIGS. 6 and 7) determined by the processor circuitry104 is a value that indicates a desired radio speaker volume (radiovolume 304) to be achieved in response to fluctuations in the volume ofthe ambient audio 105. In other words, the adjusted radio volume(element 615 below) represents a desired radio volume, the value ofwhich is calculated to maintain, in real-time, a net difference 304between the ambient audio 105 and the volume of the radio 302 (which ismanifested as the output volume of the radio speaker 102). In someembodiments, the net difference 304 is equal to the difference betweenthe ambient audio level and the baseline volume level.

In some embodiments, the radio may have a maximum volume level 306,which sets a maximum value for the radio volume 302. In accordance withsuch embodiments, when the radio volume 302 reaches the maximum volumelevel 306, the net difference 304 may not be maintained as the ambientaudio 105 continues to increase.

The radio volume control signal 108 is the control signal produced bythe processor circuitry 104 to ultimately instruct the radio to adjustthe radio volume setting (pursuant to the adjusted radio volume valuediscussed above) in real-time so that the radio volume 302 is adjustedto maintain a volume greater than the ambient audio 105, wherein thedesired difference between the radio volume 302 and ambient audio 105 isthe net difference 304 (i.e., the difference between the ambient audiolevel and the baseline volume level). Thus, as the ambient audio 105increases, the adjusted radio volume (615 below) increases, and theradio volume control signal 108 instructs the radio to increase theradio volume setting to maintain the net difference 304 between theambient audio 105 and the volume of the radio 302. Conversely, as theambient audio 105 decreases, the adjusted radio volume (615 below)decreases, and the radio volume control signal 108 instructs the radioto decrease the radio volume setting to maintain the net difference 304between the ambient audio 105 and the volume of the radio 302.

At block 205, the codec 103 receives the radio volume control signal108, and adjusts output signal 109 to control the output volume of theradio speaker 102 in response to the radio volume control signal 108,such that the volume of the output speaker 102 is adjusted to maintain avolume greater than the ambient audio 105, wherein the desireddifference between the volume of the output speaker 102 and ambientaudio 105 is the net difference 304 (i.e., the difference between theambient audio level and the baseline volume level). Thus, as the ambientaudio 105 increases, the radio volume setting is increased, and theoutput signal 109 controls the speaker 102 to increase the output volumeof the speaker to maintain the net difference 304 between the ambientaudio 105 and the volume of the speaker 102. Conversely, as the ambientaudio 105 decreases, the radio volume setting is decreased, and theoutput signal 109 controls the speaker 102 to decrease the output volumeof the speaker to maintain the net difference 304 between the ambientaudio 105 and the volume of the speaker 102.

At block 206, the process is repeated so that the volume of the radiospeaker 102 is continuously adjusted in response to the ambient audioreceived at the radio microphone 101.

Reference is now made to FIGS. 4-7, which illustrate example embodimentsof various circuitry components for performing the disclosed method forautomatically adjusting a volume setting of a land mobile radio inresponse to ambient audio. Referring first to FIG. 4, there isillustrated a block diagram of the processor circuitry/SoC 104illustrated in FIG. 1. The processor circuitry 104 includes, in someembodiments, codec interfaces 401 and 402, a digital signal processor(DSP) 403, ARM processor 404, and other components such as, for example,memory 405. It should be appreciated that additional circuitry maycomprise the various components described herein and illustrated in theaccompanying figures. Furthermore, it should be appreciated that variouscomponents described herein may be substituted with other circuitry orcomponents capable of fulfilling similar processes or purposes.

FIG. 5 illustrates an example block diagram of the DSP 403 comprisingthe processor circuitry 104. In the embodiment illustrated in FIG. 5,the DSP 403 includes initialization circuitry 510, automatic gaincontrol (AGC) circuitry 520, and level control circuitry 530. Theinitialization circuitry 510 includes preprocessing circuitry 512 andpower measurement circuitry 514. The preprocessing circuitry 512receives the processor input signal 107 from the codec 103, and cleansthe signal 107 by changing the sample rate and removing any microphonebias. The cleaned audio signal 515 is then passed to the powermeasurement circuitry 514, which measures the average power of thecleaned audio signal 515 over a window (e.g., 5 msec) to determine howmuch audio is present in the signal. An average power measurement 517 isoutput by the power measurement circuitry 514.

The average power measurement 517 is then passed to the level controlcircuitry 530, which averages the average power measurement 517 over awindow (e.g., 1 sec.) to convert the average power measurement 517 to alonger power average (e.g., 1 sec.) expressed in a dB scale. The outputof the level control circuitry 530 is the ambient audio level 535, whichis a value that is representative of a volume level of the ambient audioreceived at the microphone 101.

In some embodiments, the processor circuitry 104 may include anautomatic gain control function, wherein the audio received at themicrophone 101 is amplified for transmission. As such, the receivedaudio is presumed to be voice audio for this purpose (rather thanambient audio). In the embodiment illustrated in FIG. 5, the automaticgain control function is performed by the AGC circuitry 520. The AGCcircuitry 520 includes gain control circuitry 522, which receives theaverage power measurement 517, and averages a number of average powermeasurement 517 samples over a period of time to produce a longer poweraverage. For example, in some embodiments, the measurement 517 may beaveraged over a period of twenty samples (100 msec.) to produce thelonger power average. The longer power average is then compared to adesired power level (typically represented as a constant). Thus theoutput of the gain control circuitry 522 is a ratio 523 of the longerpower average to a desired power average. The ratio 523 is then fed intoa switch box 524.

The AGC circuitry 520 also includes circuitry 526 for receiving a dBgain level of the microphone and converting it to a linear gain level525. In some embodiments, the dB gain level may be a fixed value. Insome embodiments, the dB gain level may be programmable. The switch box524 then selects as its output the AGC ratio 523 if the AGC function isenabled, or the linear gain level 525 if the AGC function is disabled.The switch box output 527 is then multiplied with the cleaned audiosignal 515 to produce the amplified audio signal 529. It should beappreciated that, in some embodiments, the signal 529 may be reducedinstead of amplified.

FIG. 6 illustrates an example block diagram of the ARM processor 404comprising the processor circuitry 104. In the embodiment illustrated inFIG. 6, the ARM processor 404 includes automatic volume controlcircuitry 610, which receives the ambient audio level 535 from the DSPcircuitry 403 and determines the adjusted radio volume 615. The ARMprocessor 404 also receives the current volume setting 622, which isconverted to dB scale and passed to the automatic volume controlcircuitry 610 as current volume setting 630.

FIG. 7 illustrates an example block diagram illustrating an exampleembodiment of the automatic volume control circuitry 610 shown in FIG.6. In the embodiment illustrated in FIG. 7, the automatic volume controlcircuitry 610 receives the ambient audio level 535, and subtracts fromthe ambient audio level 535 a baseline volume level 620, to produce avalue 625, wherein the value 625 is the difference between the baselinevolume level 620 and the ambient audio level 535. The value 625 isequivalent to the net difference 304 illustrated in FIG. 3 and discussedabove. Next, the current volume level setting 630 is added to the value625 to produce the adjusted radio volume 615, which represents a desiredradio volume setting responsive to the ambient audio received at theradio microphone 101.

As discussed above, the current volume level setting is a value that isrepresentative of the current radio volume setting, and the baselinevolume level is a value that represents a volume level for use in aquiet environment. In some embodiments, the baseline volume level may beset manually by a user adjusting the radio volume knob to the desiredvolume setting. In other embodiments, the baseline volume level may beprogrammed into the radio as a preset value. In some embodiments, a usermay adjust the baseline volume level, even if the baseline volume levelis programmed as a preset value.

Referring again to FIG. 6, the ARM processor 404 further includes, insome embodiments, an upper volume limit 650 and lower volume limit 660,which are both converted to dB scale and may be used to set upper andlower volume limits to limit saturation of the adjusted radio volume615. In some embodiments, the ARM processor 404 may also include volumereduction circuitry 665 to reduce the adjusted radio volume 615 inaccordance with certain specifications. Additional reduction/limitercircuitry 670 may also be incorporated to ensure the adjusted radiovolume 615 is within the volume limits. The ARM processor 404 thenoutputs the radio volume control signal 108, which is output to thecodec 103 via the codec interface 402.

A number of additional and alternative embodiments of the disclosedsystem and method may be provided without departing from the spirit orscope of the present disclosure as set forth in the claims providedherein. These various embodiments are believed to be understood by oneof ordinary skill in the art in view of the present disclosure. Forexample, in some embodiments, the disclosed automatic volume controlfeature may be enabled or disabled by a radio menu or radio button. Insome embodiments, the radio may include multiple microphones. In suchembodiments, one microphone may be set to operate primarily for ambientaudio reception, and the other for voice audio. Additionally, multiplemicrophone embodiments may use an average of the audio signals generatedby the multiple microphones, or may use the highest of the audiosignals.

In some embodiments, multiple microphones may be used such that onemicrophone samples the volume at the radio unit (or next to the radiospeaker) during a call to sample the received call volume. A separatemicrophone may then be used to sample the ambient audio, which may becompared with the received call volume. The disclosed feature may thenbe used to adjust the radio volume in response to the ambient audio.Thus, if an incoming call is too quiet or loud, the speaker volume maybe adjusted accordingly.

What is claimed is:
 1. A land mobile radio for use in a land mobileradio (LMR) system, the land mobile radio configured to automaticallyadjust a current volume level setting of the land mobile radio inresponse to ambient audio, the land mobile radio comprising: a radiospeaker configured to produce output audio at an output volume based onthe current volume level setting of the land mobile radio; a firstmicrophone configured to receive the ambient audio and generate amicrophone signal in response to receiving the ambient audio; ananalog-to-digital converter configured to receive the microphone signaland generate a processor input signal based on the ambient audio; afirst circuitry configured to receive the processor input signal, and inresponse to the processor input signal based on the ambient audio,calculate a first amplitude difference between the ambient audio and thecurrent volume level setting and generate a radio volume control signalrepresentative of a value of the current volume level setting based onthe first amplitude difference; wherein the first circuitry includes afirst processor configured to provide an upper volume limit and a lowervolume limit and comprising a volume reduction circuitry to adjust thecurrent volume level setting to maintain the current volume levelsetting within the upper volume limit and the lower volume limit, adigital-to-analog converter configured to receive the radio volumecontrol signal and generate an output signal to set the value of thecurrent volume level setting of the land mobile radio such that adifference is maintained between the current volume level setting andthe ambient audio as the ambient audio both increases and decreases inamplitude and as the current volume level setting is maintained withinthe upper volume limit and the lower volume limit; and wherein the valueof the current volume level setting which is maintained within the uppervolume limit and the lower volume limit is not set when the land mobileradio is operating in a transmit state or the radio speaker of the landmobile radio is activated, and wherein the value of the current volumelevel setting which is maintained within the upper volume limit and thelower volume limit is not set in response to an activating by a user ofa radio button on the radio and is resumed to being set in response to acompleting of the activating.
 2. The land mobile radio of claim 1,wherein the difference maintained between the current volume levelsetting and the ambient audio is user adjustable.
 3. The land mobileradio of claim 1, wherein a difference between the output volume of theradio speaker and the ambient audio is preset.
 4. The land mobile radioof claim 1, wherein the analog-to-digital converter anddigital-to-analog converter comprise a codec.
 5. The land mobile radioof claim 1, wherein the first circuitry comprises the first processorfurther configured to determine the first amplitude difference, and asecond processor configured to generate the radio volume control signal.6. The land mobile radio of claim 1, wherein the first circuitry isfurther configured to produce an amplification signal representative ofan amplification of the ambient audio.
 7. A method for automaticallysetting a current volume level setting of a land mobile radio inresponse to ambient audio, the method comprising: receiving the ambientaudio at a microphone of the radio and generating a microphone signal;receiving the microphone signal at an analog-to-digital converter andgenerating a processor input signal based on the ambient audio receivedat the microphone; receiving the processor input signal at firstprocessor circuitry and determining an ambient audio level; setting avalue of the current volume level setting of the land mobile radio suchthat a difference is maintained between the current volume level settingand the ambient audio level as the ambient audio both increases anddecreases in amplitude, wherein the setting the value of the currentvolume level setting further comprises providing an upper volume limitand a lower volume limit and adjusting the current volume level settingto maintain the current volume level setting within the upper volumelimit and the lower volume limit, wherein the setting the value of thecurrent volume level setting according to the method for automaticallysetting the current volume level setting is paused in response to aradio speaker configured to produce output audio at an output volumebased on the current volume level setting of the land mobile radio beingactive or the radio operating in a transmit state; and wherein thesetting the value of the current volume level setting according to themethod for automatically setting the current volume level setting isstopped in response to an activating by a user of a radio button on theradio and resumed in response to a completing of the activating.
 8. Themethod of claim 7, wherein the difference maintained between the valueof the current volume level setting and the ambient audio level is equalto the difference between the ambient audio level in a quiet environmentand the value of the current volume level setting set by the user in thequiet environment.
 9. The method of claim 7, wherein a differencebetween the output audio volume of the radio speaker and the ambientaudio is equal to the difference between the ambient audio level in aquiet environment and the current volume level setting set by the userin the quiet environment.
 10. The method of claim 7, further comprisingproducing an amplification signal representative of an amplification ofthe ambient audio.
 11. The method of claim 7, wherein the method isrepeated continuously.
 12. The method of claim 7, wherein the ambientaudio level is representative of a volume level of the ambient audioreceived at the microphone.
 13. One or more non-transitory storage mediaembodied with computer-executable instructions that, when executed by aprocessor, perform a method for automatically setting a current volumelevel setting of a land mobile radio in response to ambient audio, themethod comprising: receiving the ambient audio at a microphone of theradio and generating a microphone signal; receiving the microphonesignal at an analog-to-digital converter and generating a processorinput signal based on the ambient audio received at the microphone;receiving the processor input signal at first processor circuitry anddetermining an ambient audio level; calculating, by the first processorcircuitry, in response to the processor input signal representative ofthe ambient audio, a first amplitude difference between the ambientaudio level and the current volume level setting; generating a radiovolume control signal representative of a setting of the current volumelevel setting based on the first amplitude difference; receiving theradio volume control signal and setting the current volume level settingof the land mobile radio such that a difference is maintained betweenthe adjusted radio volume and the ambient audio as the ambient audioboth increases and decreases in amplitude, wherein the setting thecurrent volume level setting further comprises providing an upper volumelimit and a lower volume limit and adjusting the current volume levelsetting to maintain the current volume level setting within the uppervolume limit and the lower volume limit, wherein the setting the valueof the current volume level setting according to the method forautomatically setting the current volume level setting is paused inresponse to a radio speaker configured to produce output audio at anoutput volume based on the current volume level setting of the landmobile radio being active or the radio operating in a transmit state;and wherein the setting the value of the current volume level settingaccording to the method for automatically setting the current volumelevel setting is stopped in response to an activating by a user of aradio button on the radio and resumed in response to a completing of theactivating.
 14. The one or more non-transitory storage media of claim13, wherein the difference maintained between the adjusted radio volumeand the ambient audio is user adjustable.
 15. The one or morenon-transitory storage media of claim 13, wherein a difference betweenthe output audio volume of the radio speaker and the ambient audio isequal to the difference between the ambient audio level in a quietenvironment and the current volume level setting set by the user in thequiet environment.